Make a directory and change to it

A basic shell function to create a directory and change to it goes like this:

mkcd () { mkdir "$1" && cd "$1"; }

This works well in many cases but breaks in unusual cases (e.g. if the argument begins with -).

I'm writing a more sophisticated version. This version calls mkdir -p to create parent directories if needed and just change to the directory if it already exists. It has these design goals:

• Work in any POSIX compliant shell.

• Cope with any file name.

• If the shell has logical directory tracking, where foo/.. is the current directory even if foo is a symbolic link to a directory, then the function must follow that logical tracking: it must act as if the cd builtin was called and magically created the target directory.

• If a directory is created, it is guaranteed that the function changes into it, as long as there is no race condition (another process moving a parent directory, changing relevant permissions, …).

Here is my best current effort. Does it meet the goals above? Are there situations where the behavior is surprising?

mkcd () {
case "$1" in
/..|/../) cd -- "$1";; # that doesn't make any sense unless the directory already exists
//../) (cd "${1%/../}/.." && mkdir -p "./${1##/../}") && cd -- "$1";;
/*) mkdir -p "$1" && cd "$1";;
/../) (cd "./${1%/../}/.." && mkdir -p "./${1##/../}") && cd "./$1";;
../*) (cd .. && mkdir -p "${1#.}") && cd "$1";;
*) mkdir -p "./$1" && cd "./$1";;
esac
}


Some error messages may be confusing like:

$ mkcd /foo/../bar
mkcd:cd:3: no such file or directory: /foo/..
$ mkcd /bin/../bar
mkdir: cannot create directory `./bar': Permission denied

Probably not much you can do about that.

StackExchange Code Review Q#21082, answer score: 3